Design of machine Elements Interview Questions with Answers (Shafts, Keys, Bolts, Nuts, Screws, fasteners, Bearings, Flywheel & Governor) 1. Define the term critical speed. The speed, at which the shaft runs so that the additional deflection of the shaft from the axis of rotation becomes infinite, is known as critical or whirling speed. 2. Factors considered designing a shaft? Strength and Stiffness 3. What is a key? What are the types of keys? A key is device, which is used for connecting two machine parts for preventing relative motion of rotation with respect to each other. The different types of keys are Saddle key Tangent key Sunk key Round key and taper pin 4. What is the main use of woodruff keys? A woodruff key is used to transmit small value of torque in automotive and machine tool industries. The key-way in the shaft is milled in a curved shape whereas the key way in the hub is usually straight. 5. What are the various failures occurred in sunk keys...